This invention relates to an improved lavatory sink assembly and particularly to one having an overflow duct adhesively bonded to the lavatory sink bowl.
Lavatory sinks of the type widely used in residential and commercial settings include an overflow port which permits the sink to be filled to a predetermined level and then provides an overflow passage which drains the water to prevent the bowl from overfilling.
Lavatory sinks are typically made from stamped sheet metal. Durable surface coatings such as porcelain enamel are applied to the exposed inside surface of the sink bowl and its outside surface. These coatings improve the appearance of the sink, enable it to be easily cleaned, and provide corrosion protection. A typical present design for a lavatory sink assembly includes an overflow duct separately formed from sheet metal which is spot welded to the stamped sink bowl prior to the application of surface coatings. Although such prior art configurations perform satisfactorily, they have a number of shortcomings. Spot welding of the overflow duct can cause spot welding marks in the finished sink which are cosmetically undesirable. The area of the spot welds further has a tendency of preventing good adhesion of the surface coating which can cause the enamel to flake or pop off over time. Spot welding requires clean metal surfaces and therefore the components must be welded together prior to surface coating. The irregular surface formed by the fabricated assembly is difficult to uniformly coat with enamel, and further, some areas such as the inside of the overflow duct are shielded and cannot be easily coated, thus leading to the potential for corrosion problems. And, finally, spot welding by itself does not provide a leak free joint between the duct and bowl, and therefore separately applied sealant or heavy surface coatings are required.
In view of the foregoing, there is a need to provide an improved lavatory sink assembly which avoids the above outlined problems of prior art designs. The improved lavatory sink assembly according to the present invention employs an overflow duct, preferably made from molded plastic, which is affixed to the lavatory sink bowl using adhesives. The assembly in accordance with the present invention is preferably fabricated using a manufacturing process in which the lavatory bowl is first coated on both its inside and outside surfaces without the overflow duct in place, enabling the bowl to be uniformly and completely covered. Thereafter, the overflow duct is bonded to the sink bowl. With this assembly technique, problems associated with the cosmetic appearance and corrosion of spot welded assemblies are obviated.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings.